Silica Based Non-linear Optical Devices

二氧化硅基非线性光学器件

• 批准号: RGPIN-2014-05072
• 负责人: Smelser, Christopher
• 金额: $ 1.6万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633217
• 关键词: Silica; Based; Non; linear; Optical

Silica glass has long been the preferred material for waveguides in optical telecommunications networks and sensor applications. Currently, most of the existing telecommunications network is composed of silica fiber or waveguides. As a result of the wide deployment of silica based infrastructure, silica components can be made relatively inexpensively. While silica has many desirable properties it has one significant drawback in that it is an amorphous material that does not possess a second order optical non-linearity (SON). The SON is important as this property can be exploited to produce devices like optical modulators or frequency converters. Optical modulators are a major component in current telecommunications networks and wavelength converters have the potential to significantly impact future networks, fiber lasers, and cryptography. Currently, the crystal lithium niobate is used for these types of applications because it is not amorphous and possesses a large SON. Lithium niobate would be a perfectly acceptable solution if it were not for the fact that its index of refraction and thermal expansion are not compatible with the existing silica based infrastructure. In addition to the incompatibility issues, lithium niobate is more expensive and is not as easily formed into the variety of components necessary for many applications.In a perfect world, we would be able to use a silica based device that has a large SON instead of lithium niobate. Two decades ago researchers did actually discover a method, called thermal poling, to create a SON in silica (of about 1 pm/V) but have been unable to increase it to the same level as lithium niobate (about 80 pm/V). Recently we were conduction thermal poling experiments on micro and nano-layered structures in silica and made a startling discovery. Our measurements suggested that the SON in our samples could be as much as 14x higher than previously achievable. Such an increase would result in a SON that is much closer to that of lithium niobate. It is the goal of this research proposal to capitalize on this potential breakthrough and continue to study these structures to see whether we can eventually produce devices capable of competing with lithium niobate. The program will begin with a closer look at the structures themselves to see whether they can be optimized to produce even larger non-linearities. This could involve altering the composition of the glass or changing the spacing/thickness of the layers. We will also produce simulations that we hope will explain the reason for the observed increase in SON.After a considerable amount of work has gone into perfecting the layer structures we hope to move on to producing waveguides that incorporate micro and nano-layers. My students will begin by designing the basic structures using modeling software and then will attempt to develop them in our fabrication facility. We will also be seeking industry partners to develop low loss waveguide structures that incorporate micro and nano-layers. If we are successful in developing micro and nano-layer waveguides we intend to test them as modulators and wavelength converters to determine if there is a significant improvement over pre-existing silica glass based devices. Successfully producing silica based devices with large SON's would represent a major breakthrough and would impact virtually all aspects of the Canadian Photonics industry. We believe that our studies indicate that such a breakthrough could be on the horizon.

长期以来，二氧化硅玻璃一直是光通信网络和传感器应用中波导的首选材料。目前，现有的电信网络大部分由石英光纤或波导组成。由于二氧化硅基基础设施的广泛部署，二氧化硅组件的制造成本相对较低。虽然二氧化硅具有许多理想的特性，但它有一个显着的缺点，因为它是一种不具有二阶光学非线性 (SON) 的无定形材料。 SON 很重要，因为可以利用这一特性来生产光调制器或频率转换器等设备。光调制器是当前电信网络的主要组件，波长转换器有可能对未来的网络、光纤激光器和密码学产生重大影响。目前，晶体铌酸锂用于这些类型的应用，因为它不是非晶态的并且具有较大的SON。如果不是因为铌酸锂的折射率和热膨胀与现有的二氧化硅基基础设施不兼容，那么铌酸锂将是一种完全可以接受的解决方案。除了不兼容性问题之外，铌酸锂更昂贵，并且不容易形成许多应用所需的各种组件。在完美的世界中，我们将能够使用具有较大 SON 的二氧化硅基器件来代替铌酸锂。二十年前，研究人员确实发现了一种称为热极化的方法，可以在二氧化硅中产生 SON（约 1 pm/V），但无法将其提高到与铌酸锂（约 80 pm/V）相同的水平。最近，我们对二氧化硅中的微米和纳米层状结构进行了传导热极化实验，并取得了惊人的发现。我们的测量结果表明，我们样品中的 SON 可能比以前高出 14 倍。这种增加将导致 SON 更接近铌酸锂。这项研究计划的目标是利用这一潜在突破并继续研究这些结构，看看我们最终是否能够生产出能够与铌酸锂竞争的设备。该计划将首先仔细观察结构本身，看看是否可以对其进行优化以产生更大的非线性。这可能涉及改变玻璃的成分或改变层的间距/厚度。我们还将进行模拟，希望能够解释所观察到的 SON 增加的原因。在完成大量工作来完善层结构之后，我们希望继续生产包含微米层和纳米层的波导。我的学生将首先使用建模软件设计基本结构，然后尝试在我们的制造工厂中开发它们。我们还将寻求行业合作伙伴来开发包含微米层和纳米层的低损耗波导结构。如果我们成功开发出微米层和纳米层波导，我们打算将它们作为调制器和波长转换器进行测试，以确定是否比现有的基于石英玻璃的设备有显着改进。成功生产具有大型 SON 的二氧化硅基器件将代表重大突破，并将影响加拿大光子学行业的几乎所有方面。我们相信，我们的研究表明这样的突破可能即将到来。